Technical Abstract:
To determine molecular mechanisms that regulate uterine development in the pig a custom microarray was developed to profile differential gene expression. Oligonucleotides (70 mer) were produced from sequenced ESTs from the Meat Animal Research Center, ARS, USDA libraries that had at least 90% homology to known genes in The Institute of Genome Research pig gene index. Total uterine RNA was isolated from gilts at 90, 150, and 210 days (d) of age and dye labeled cDNA probes were hybridized to arrays representing about 600 pig genes involved in growth and reproduction. Quantitative analysis using a mixed linear model statistical program identified(P<0.01) 45 genes differentially expressed from 90 to 210 d of age, which included growth factor/hormone receptors, growth and cell cycle regulators, apoptosis and seven transcription factors. The gene bone morphogenetic protein 4, a structural protein and signaling growth factor, was down regulated at 90 d and up-regulated at 150 d. The gene for zona pellucida glycoprotein 3A (sperm receptor) was up-regulated by 150 d and oviductil glycoprotein 1 was up-regulated by 210 d. Both of these genes play a role in the fertilization process and/or early embryonic development. A number of these differentially regulated genes expressed in the pig have not been reported in the human or the pig, including melanocortin 3 receptor and PPAR gamma coactivator 1.These results demonstrate, for the first time, differentially expressed uterine genes in the prepuberal pig. The temporal expression of these key genes that regulate uterine development and function during the prepuberal period will lead to a better understanding of the molecular mechanisms controlling fertilization and early embryonic development.